Tubular power saw

ABSTRACT

I disclose a cutting apparatus the combination comprising a base, an elongated tubular inner cutter, extending parallel to the base and rotatably supported in cantilever fashion from said base, a tubular outer cutter rotatably mounted on the base and substantially concentrically of said inner cutter but spaced longitudinally from the point of cantilever support of said inner cutter, means for rotating said cutters, and means for feeding an elongated workpiece from which a tubuliform member is to be cut to said inner and outer cutters, said longitudinal spacing approximating the anticipated length of said workpiece.

United States Patent Inventor Robert J. Monahan Sewickley, Pa. Appl. No. 11,352 Filed Feb. 13, 1970 Patented Dec. 28, 1971 Assignee William A. Bayer Pittsburgh, Pa.

TUBULAR POWER SAW 12 Claims, 8 Drawing Figs.

U.S. C1 143/85, 77/69, 144/20, 83/1 Int. Cl B27b 5/12, B27b 3 3/ l 8 Field of Search 143/85 R, 85 A; 144/20, 23; 77/69, 58, 5; 83/1 References Cited UNlTED STATES PATENTS 3/1902 Anderson 1,356,019 10/1920 See 3,203,456 8/1965 Witshnig Primary Examiner- Donald R. Schran Attorney- Don J. Smith ABSTRACT: I disclose a cutting apparatus the combination comprising a base, an elongated tubular inner cutter, extending parallel to the base and rotatably supported in cantilever fashion from said base, a tubular outer cutter rotatably mounted on the base and substantially concentrically of said inner cutter but spaced longitudinally from the point of cantilever support of said inner cutter, means for rotating said cutters, and means for feeding an elongated workpiece from which a tubuliform member is to be cut to said inner and outer cutters, said longitudinal spacing approximating the anticipated length of said workpiece.

PATENTED UEC28 I97! SHEET 1 0F 3 INVENTOR Robert J. Monohon TUBULAR POWER SAW The present invention relates to an improved tubular cutting apparatus for making articles with arcuate or circular surfaces and more particularly to such apparatus having means for'supporting and rotating two or more generally tubular saw blades for producing hollow cylindrical articles or the like.

In the manufacture of insulating materials for coverings for pipes, conduits and the like, it is desirable to form the insulating material, such as cork, foamed glass, foamed or expanded polymerized styrene (e.g. styrofoam) into blanks or workpieces, and then to shape the blanks of material to fit about such pipes or the like by sawing them into arcuate segments. In such manufacture, it is desirable as a preliminary step to saw the blanks longitudinally in half and then to shape the halves so that the latter form a continuous covering when placed in juxtaposed position about the pipes or the like. For a maximum rate of production, it is desirable to shape the armate segments simultaneously from the blank halves to facilitate handling thereof. With this arrangement, a pair of such arcuate segments, after shaping, can be readily removed from the cutting apparatus. It is also advantageous from a production standpoint to arrange the cutting apparatus so that a given pair of the blank halves or workpieces can be pushed or fed through the apparatus by succeeding pairs of such workpieces.

These and other objects, features and advantages of the invention, together with structural details thereof, will be elaborated uponduring the forthcoming description of an exemplary modification of the invention, when taken in conjunction with the accompanying drawings wherein:

FIG. 1 is an isometric view of one form of cutting apparatus arranged in accordance with the invention;

FIG. 2 is a cross-sectionalview of the apparatus of FIG. 1 taken along reference line II-II thereof;

FIG. 3 is a partially longitudinally sectioned view of the apparatus of FIG. 1 and taken along reference line III-Ill thereof;

FIG. 4 is another cross-sectional view of the apparatus of FIG. 1 taken generally along reference line lV-IV thereof;

FIG. 5 is an enlarged, partial view of an alternative cutting head arrangement which can be used with the cutting apparatus of the preceding figures;

FIG. 6 is a side elevational view of an alternative feed mechanism for use with the cutting apparatus of the preceding figures;

FIG. 7 is a top plan view of the apparatus of the preceding figures;

FIG 8 is an end elevational view of the apparatus shown in FIG. 6.

Referring now more particularly to the drawings, the cutting apparatus 10 is illustrated therein as mounted upon a bench or table designated generally by reference character 12. The apparatus 10 includes a base structure including an elongated platform 14, which is suitably apertured to accommodate drive belts 16 and 18 and a stock feed mechanism designated generally by reference character 19, all of which are described in greater detail below. The platform 14 is supported adjacent its ends by tabs 13 and which engage the end portions of the table 12. The tabs 13 and 15 define a necked down or narrower intermediate portion 144 of the platform, for purposes described below.

Mounted upon the platform 14, in this example, are a pair of bearing housings 20 and 22, each of which is arranged to retain a sleeve-type bearing 24. A tubular drive shaft 26 is rotatably mounted in the bearings 24 and is rigidly joined at its inward end to an adjustable chuck member 28 for rotation therewith. The chuck 28 is conventional in construction and is adapted to rotate an inner tubular saw or cutter 30 when the latter is clamped therein. Various diametric sizes of the cutter 30 can therefore be accommodated by the apparatus 10, within the structural limits of the chuck 28.

With the arrangement described thus far, the inner cutter 30 and the chuck 28 are supported in cantilever fashion by the bearings 24 and their housings 20 and 22. To reduce the cantilever loading upon the endmost bearing housing 20, an auxiliary hold down strap 32 can be employed. The hold down strap 32 rides in or upon a suitable journal or bearing (not shown) on the drive shaft 26. The hold down strap 32 in this example is secured to the apparatus platform 14 by suitable fastening means such as mounting bolts.

The other end of the inner tubular cutter 30 extends spacedly through central apertures 34 (FIGS. 2 and 3) in outer saw or cutter supports 36 and 38, which are mounted vertically upon an auxiliary platform 37 as better shown in FIG. 3. The platform 37 extends transversely of the table 12 and is furnished at its ends with relatively short leg portions 35 engaging table beams 33 respectively, to which they are secured by suitable bolts (not shown). The platform 37 thus bridges the intermediate table portion 14a and permits the platform, cutter supports 36 and 38, and outer cutter 40 to be moved therealong to accommodate longer or shorter inner cutters 30 as desired, for similar variations in length of workpieces. The inner cutter 30. preferably is supported coaxially of the apertures34, which are circular in this example, by means of the cantilevered bearing arrangement 20-24 described above. A flanged sleeve-type bearing 39 (FIGS. 2 and 3) is closely fitted within each of the apertures 34..The relatively shorter outer tubular saw or cutter 40 is rotatably mounted in the aforementioned bearings 39 and thus is supported for rotation by means of the supports 36 and 38. The bearings 39 are mounted with retaining rings 41 which are welded or otherwise secured in the apertures 34 of the supports 36 and 38.

The outer cutter 40 includes a tubular drive shaft 43 rotatably mounted in the sleeve bearings 39 and longitudinally retained therein by end flange 45 and a pair of lockn uts 47. Intermediate the supports 36 and 38, a drive pulley 49 and brake drum 5] are secured to the outer surface of the drive shaft 43 for controlling the operation thereof. At the outer end of the drive shaft 43, adjacent the support 38, a cutter adapter 53 is threadedly secured to the shaft. A tubular cutter head or saw 55 is detachably secured to the adapter 53 by a number of setscrews 57. In this example, the supports 36 and 38 are stabilized by a pair of stringers or braces 59, which are bolted to the upper edges of the supports. The outside and inside diameters of the inner tubular cutter 30 and the outer cutting head 55, respectively, are selected such that the annular space 42 therebetween conforms to the desired thickness of the insulation or other finished article. In addition the outside diameter of the inner cutter 30 is equivalent to the outside diameter of a given pipe or conduit for which insulation material is being manufactured.

Desirably the inner cutter 30 is rotated in reverse direction relative to the outer cutter 40 in order to reduce the net torque imparted to the workpieces.

It will be understood that both the outer and inner cutters 30 and 40 can be elongated in cantilever fashion and thus inserted spacedly and concentrically through a second pair of cutter supports (not shown) mounted as are the supports 36 and 38. A third tubular cutter (not shown) can then be mounted on the second cutter supports at the cantilevered extension of the cutters 30 and 40 and in the manner described herein for the outer cutter 40. With the latter arrangement two complementary sizes of pipe insulation or other articles can be shaped simultaneously.

The distance between the inner end 44 of the chuck 2 8 and cutting edges 64 and 66 of the inner and outer cutters is greater than the anticipated length of the insulation blanks or other workpieces so that the latter can be readily removed from the saw apparatus simply by separating the shaped halves of the blanks and removing from around the shank 46 of the inner cutter 30, as succeeding blanks push the shaped halves past the inner or adjacent end of the outer shaft 43. A guide plate 48 is secured to the platform 14 in this area to facilitate unloading the machine from one side thereof.

Intermediate the bearing housings 20-22 a drive pulley 52 or the like is mounted on the chuck drive shaft 26. The pulley 52 is pinned or otherwise rigidly secured to the aforementioned drive shaft 26 for rotation of the shaft and of the chuck 28. The pulley and drive shaft 52, 26 are driven by means of the aforementioned belt 16 extending through an aperture 56 in the platform 14, and a drive shafi and pulley arrangement denoted generally by reference character 58 and mounted upon the base structure cross bracing, as shown in FIG. 1 of the drawings. The shaft and pulley 58 are driven by a suitable inner cutter drive motor (not shown). The chuck-'28 when thus rotated, rotates the inner cutter 30 which is spacedly inserted through the outer cutter 40. In a similar manner, the outer cutter 40 and its pulley 54 are rotated by means of the belt 18 and outer cutter drive motor 62.

Each of the inner and outer cutters 30, 40 is provided with suitable cutting teeth 64 or 66 respectively on their adjacent end edges (FIGS. 1 and 3). The outer cutter 40 in addition is provided with a generally circular flange member 68 disposed adjacent its cutting teeth and of sufficient diameter to engage the outer corners of the two blank portions fed simultaneously thereto. The flange portion 68 of the outer cutter head 55 curves inwardly in a relatively smooth arcuate sweep to the outer cutter head teeth 66. As better shown in FIG. 4, the arcuate portion 67 of the flange 68 is provided with elongated generally longitudinally extending teeth 69. The teeth 69 are thus disposed for grinding up the waste cut from the outer surfaces of the half cylinders passing through the annular space 42 between the cutters. The array of the grinding teeth '69 is twisted slightly between the main, outer cutting teeth 66 and the outermost or peripheral edge 71 of the flange 68 to facilitate cutting and grinding by angular engagement with the waste. The arcuate contour of the grinding teeth 69 provides an angular engagement in the other direction and thus reduces the force required to push the blanks through the machine.

Another form of outer cutter head 55' is illustrated in FIG. 5. In the latter arrangement the head 55 is provided with a flat, generally circular flange 73, having grinding teeth 70 and choppers 72 whereby the waste material removed from the comer portions of the insulation block is chopped into manageable fragments.

As noted previously, the chuck 28, which is adjustable in the conventional manner, can be adapted to support different sizes of tubular cutters similar to the inner cutter 30 such that insulation members for differing pipe sizes can be cut with the cutting apparatus of the invention. Similarly, the outer saw supports 36 and 38 are bolted, as shown in FIG. 3, or otherwise detachably mounted on the platform 37 so that other supports having different sizes of apertures 34 can be utilized to accommodate an outer cutter of a different size. Thus, the radial thickness of the shaped insulation or other workpieces, or the internal diameter thereof, or .both can be varied as required.

When the insulational or other workpiece blank 74, which is precut longitudinally into half portions, is to be fed into inner and outer cutters 30, 40, the blank 74 is placed upon an adjustably mounted platform 76 having a pair of vertical guide plates 78 in longitudinal and spaced alignment with the inner and outer cutters. Vertical alignment of the blank 74 can be achieved by raising or lowering the adjustable platform 76, by means of slotted mounting brackets 80 and suitable mounting bolts 82 secured to the edges of the intermediate table portion 14a. Additional apertures for the bolts 82 can be drilled and tapped along the table edges so that the feed platform 76 can be moved with the outer cutter platform 37 when desired. The adjustable platform 76 is further provided with a longitudinally extending slot 84 for the purpose of accommodating the stock or blank feeder 86.

The feeder 86 is mounted for longitudinal movement along the apparatus platform 14 by means of its lateral, longitudinally extending grooves 88 whereby the feeder 86 engages a pair of parallel slideway members 90 as better shown in FIG. 1 of the drawings. In this example, the slideways 90 extend along the length of the intermediate platform portion 14a to rigidize the latter and to pennit proper positioning and adjustment of the feeder 86 relative to the outer cutter and feed platforms 37 and 76, when the latter are moved. In some cases it will be necessary to change the relative length of pull rod 92. The feeder 86 is actuated along the plate defined by the slideways by means of the pull rod 92 and pull rod cylinder 94, which is actuated by a hydraulic system including a pump 96 and drive motor 98 therefor, and a storage tank 100. The flow of fluid to and from the pull rod cylinder 94 is controlled by a solenoid valve 102 which in turn is actuated through appropriate conventional circuitry (not shown) by means of the limit or reversing switch 50 noted above and by a limit switch 104, which is mounted for operation by the feeder 86 at the end of its return stroke.

In the operation of the cutting apparatus, the precut halves of the insulation or other stock are placed together between the guide plates 78 of the adjustable platform 76, where they are retained by the plates 78 essentially as one workpiece designated by the reference character 74. Start switch 106 is then actuated which in turn, through suitable circuitry (not shown), energizes the inner cutter and outer cutter drive motors 60 and 62, respectively; and at the same time, causes the solenoid valve 102 to actuate the double acting pull rod cylinder 94. The cylinder 94 is arranged to effect a slow transit of the pull rod 92 in the forward direction at the speed corresponding to the cutting speed of the cutters 30 and 40 for a given workpiece material. The stroke of the pull rod 92 is such that the feeder 86 terminates its forward progress just short of the cutting teeth 64, 66 at which point the inner end of one of the cut halves thereof engages the suitably positioned reversing switch 50. The reversing switch 50 preferably is provided with a latch-type actuator which allows the cut half cylinder to pass under it while the next succeeding workpiece pushes the half cylinders clear of the inner end of the outer cutter shaft 43.

When the preceding finished articles are thus freed from the tubular shaft 43 the cut half cylinders are unloaded from the machine platform 14 into a suitable hopper or bin (not shown), either manually or by other suitable means. When the cut articles are thus removed, the actuator of the switch 50 returns to its initial position for engagement by the succeeding out half cylinder. Actuation of the reversing switch 50 in this manner energizes through suitable circuitry (not shown) the solenoid valve 102 causing the cylinder 94 to quickly return the pull rod 92 to its original position, where a stud 108 engages the limit switch 104 to again actuate the solenoid valve 102 such that the cylinder and pull rod 92, 94 are returned to their forward or feeding strokes of the feeder 86. The limit switch 104 can be coupled directly to solenoid valve 102 for a fully automatic feeding operation, or through start switch 106 (or similar separate switch not shown), for manual control of the feeding operation. Each time the feeder is moved to the limit switch 104 a succeeding pair of blank halves 74 are inserted between the guide plates 78, either manually, or automatically from suitable dispensing apparatus such as that shown schematically in FIG. 6.

The composite core 110 which has been severed by the inner cutter 30, is pushed through inner opening 11] extending uninterruptedly through the inner cutter shank 46, by action of the feeder 86. It engages the preceding core 110'which has been removed by the inner cutter 30 from a preceding pair of blanks, and pushes the core 110' out of the inner cutter shank 46, and into the chuck 28 and chuck drive shaft 26. The waste cores 110, 1 10', etc., then drop out the rear or drive end of the machine, as denoted by core 110", where the cores can be collected by a suitably placed hopper (not shown). The chuck 28 and chuck drive shaft 26 are provided with central longitudinal openings 112 and 114, respectively, extending therethrough in substantial alignment with the inner cutter shank opening 111. The openings 111, 112 and 114 communicate, and the rearmost one of them, 114, opens at the rear of the machine as denoted by reference character 116 to provide an uninterrupted exit path for the cores 110, etc.

Referring now to FIGS. 6-8 of the drawings, an alternative feed arrangement for the cutting machine of FIGS. 1-5 is illustrated, with the cutting machine 10 being illustrated partially in FIG. 6. The feed mechanism 118 is provided with a platform 120 whose elevation can be adjusted by means of handwheel 122 and intervening mechanical linkages presently to be described. The platform 120, when the alternative feed mechanism 118 is utilized, therefore replaces the feed platform 76 shown in FIGS. 1 and 4.

The pusher or feeder 86 and associated driving components are replaced by, in this example, a pair of endless chains 124 as better shown in FIGS. 7 and 8 and a plurality of pusher members 126 secured at spaced locations along the chains 124 in the manner described below. Although a pair of chains 124 are illustrated it will become obvious as this description proceeds that a single chain can be utilized with appropriately shaped pushers 126, depending upon the size of the workpieces, etc. The feed arrangement of FIGS. 6-8 therefore need not be reversed as will be apparent hereinafter and is more adapted to a fully automatic or automated operation particularly when employed in conjunction with an automatic workpiece or blank dispenser denoted schematically at 128. The dispenser 128 is arranged to discharge a workpiece or blank 74' upon the table 120 where it falls between the moving pusher members 126. The operation of the dispenser 128 is controlled by actuation of a limit switch 50' or alternatively by limit switch 50' When the switch 50' is utilized, it is placed so that it is actuated by the forward, finished end of a preceding workpiece 74" while the switch 50" is positioned to be actuated as the rearward end of the partially cut blank 74" leaves the switch actuator therefor.

In this arrangement of the invention, the endless chains 124 are supported upon respective pairs of sprockets 130 and 132, as better shown in FIG. 7 which in turn are rotatably mounted by means of axles and axle housings denoted generally by the reference characters 134. The axle housings are secured adjacent the forward and rearward ends of a pair of supporting channels or beams 136. Suitable means (not shown) are provided for driving either pair of sprockets 130 or 132. The upper strand 124a of each chain is supported throughout its length by a pair of spaced rigid stringers 138 and 140, which are secured to supporting standards 142. The stringers 138 and 140 are substantially coextensive with the free length of the upper strand of the chain between the associated pair of sprockets 130, 132. The upper stringer 138'prevents upper displacement of the chain strand 134a at and between the top portions of where the sprockets 130 and 132 are pivotally engaged with the chain, as described more fully below. The lower stringer 140, which terminates short of each sprocket 130 or 132 similarly prevents downward chain displacement.

As better shown in FIG. 8, each pusher 126 is of an inverted, generally U-shaped configuration and thus includes a horizontal pusher bar 144, as viewed in the drawings, to each end of which is secured normally upstanding L-shaped bracket 146. Substantially at the corner of the L-shaped bracket 146 is a sleeve bearing 148 provided for receiving an inwardly extending stub shaft 150. By means of their stub shafts 150, the pushers 126 are pivotally secured at desirably equal-spaced locations along the length of the chains 124. Thus each pushers 126 is pivotally joined at its ends to the respective chains 124. Adjacent the rear end of the leg portion of each L bracket 146 an inwardly projecting stub shaft 152 is secured upon which is rotatably mounted a cam wheel 154. The cam wheels 154 of each pusher 126 respectively engage a pair of rigid cam strips 156 which are likewise secured to associated ones of the sup ports 142, as better shown in FIG. 8 of the drawings. The rear end portions of the cam strips 156 are provided with camming surfaces 158 to facilitate raising the pushers 126 to their vertical positions as they round the upper portions of the rear sprockets 132. The pushers 126 are thus maintained in their upright positions against the reactional forces exerted thereon by the workpieces such as the workpiece 74" when the latter is pushed through the cutters 30' and 40' (FIG. 6). The cam wheels 154 of course prevent backward pivoting of the pushers 126 while the chain supporting stringers 138, prevent raising or lowering of the pushers 126.

Desirably, suitable means are provided for adjusting the elevation of the workpiece table 120 so as to align the workpieces with the cutters 30 and 40. If desired, the table 120 can be provided adjacent its lateral edges with a pair of upstanding guideplates (not shown) of relatively narrow profile so as not to increase unduly the height of the pushers 126. In such cases, the upstanding portions of the L brackets 146 can be lengthened so as to raise the pusher bars 144 above the upper lateral edges of the aforesaid guideplates.

One arrangement for raising and lowering the table 120 includes the provision of a unique toggle arrangement of the invention. In this example, the toggle arrangement includes pairs of link members 160 and 162 with the smaller links 162 each being about half the length of a longer link 160. The shorter link member 162 is pivotally joined to the longer link member at the midpoint of the latter and at its other end to a fixed pivot 164 secured to the framework of the feed mechanism. At each end of the table 120 the longer link members 160 are respectively secured at their upper ends to a pair of reinforcing strips 166 for the table 120 and at their lower ends to a common axle 168. Each axle 168 is secured adjacent its midpoint to a threaded collar 170.

The threaded collars are moved toward and away from one another by means of a drive shaft 172 which is rotatably mounted centrally and longitudinally of the supporting framework of the feed mechanism by a pair of apertured brackets 174. The end portions of the drive shaft 172 are reversely threaded for respective engagement with the threaded collars 170 to effect movement thereof toward and away from one another depending upon the directional rotation of the drive shaft 172. In this example, the drive shaft 172 is rotated by a cooperating pair of bevel gears 174 and 176 affixed to the drive shaft 172 and the handwheel shaft 178 respectively for rotation therewith.

When the threaded collars 170 are moved outwardly adjacent the ends of the drive shaft 172, the link members 160, 162 are moved to their uppermost or extended positions denoted by the solid outlines thereof in FIG. 6. On the other hand, when the handwheel 122 is rotated in the opposite direction to move the threaded collars to the inward limits of travel, the link members 160, 162 are withdrawn to their retracted positions as denoted by their dashed outlines 160' and 162' as shown in FIG. 6. The aforedescribed limits of adjustability of the link members represent substantially the up.- permost and lowermost positions of the table 120.

In the operation of the feed mechanism as illustrated in FIGS. 6-8, the operative condition of the mechanism (FIG. 6) is such that either the dispenser actuating switch 50' or 50 has just been actuated causing the dispenser to deposit a succeeding workpiece of blank 74 upon the table 120 where it is engaged by the adjacent pusher 126a, for movement thereby toward the cutters 30, 40. At the same time, the pusher l26b is moving the final portion of the preceding blank 74" through the cutters 30', 40. Continued movement of the chains advances the pusher 126b and the workpiece 74" to the position thereof indicated by the partial dashed outline 74" whereupon the pusher 126b becomes disengaged from the adjacent ends 180 of the cam strips 156 as denoted by its dashed outline 1261;. At this point continued movements of the chains 124 disengage the pusher bar 144 of the pusher l26b' from the workpiece 74', and the latter then remains motionless while further movement of the chains 124 and pusher 126a closes the gap between the rear end of the workpiece 74" and the succeeding workpiece. The end portion 74" of the workpiece is then pushed through the cutters 30', 40' by engagement with the forward end of the workpiece 74'. Thereafter, continued movement of the workpieces and the pushers 126 causes succeeding workpieces to actuate the dispenser switch 50 or 50" and the cyclic operation of the feed mechanism is repeated.

it should be noted that, as the cam wheels 154 of the pushers 126 are successively freed from the forward ends 180 of the cam strips 156, the pushers become freely pivoted to the chains 124 to minimize interference waste and other obstacles during their return passage on the lower strands 12412 of the chains.

From the foregoing it will be seen that a novel and efficient cutting apparatus for making tubular cuts and the like has been described herein. The apparatus is capable of making rapid, repetitive cuts of carefully controlled contours. As described, the apparatus is capable of semiautomatic or completely automated operation as desired. The descriptive and illustrative materials employed herein, therefore, are utilized for purposes of exemplifying the invention and not in limitation thereof. Accordingly, numerous modifications of the invention will occur to those skilled in the art without departing from the spirit and scope of the invention. Moreover, it is to be understood that certain features of the invention can be used to advantage without a corresponding use of other features thereof.

1 claim:

1. A cutting apparatus the combination comprising a base, an elongated tubular inner cutter extending parallel to the base and rotatably supported in cantilever fashion from said base, a tubular outer cutter rotatably mounted on the base substantially concentrically of said inner cutter but spaced longitudinally from the point of cantilever support of said inner cutter, means for rotating said cutters, and means for feeding an elongated workpiece from which a tubuliform member is to be cut to said inner and outer cutters, said longitudinal spacing approximating the anticipated length of said workpiece.

2. The combination according to claim 1 wherein said outer tubular cutter is provided with an outwardly extending flange thereon adjacent the cutting end thereof, said flange having cutting means thereon for fragmenting the outer waste material cut from said workpiece.

3. The combination according to claim 1 wherein said inner cutter is tubular and has an opening at each end in order to accommodate inner waste material from said workpiece, and the rotating means for said inner cutter is provided with an aligned opening therethrough in communication with said inner cutter opening so that said inner waste material is pushed therethrough by succeeding workpiece inner waste material and out of said apparatus.

4. The combination according to claim 3 wherein said inner cutter rotating means includes an adjustable chuck having a generally central opening extending longitudinally therethrough and an open ended tubular drive shaft secured to said chuck for rotation therewith, the opening of said tubular shaft communicating with said chuck opening therethrough with said tubular cutter opening.

5. The combination according to claim 1 wherein said outer cutter is rotatably mounted upon a movable platform, said platform being supported by said apparatus and movable longitudinally thereon relative to said chuck, said platform being detachably secured at selected positions along the length of said apparatus to accommodate differing lengths of inner cut ters secured in said chuck.

6. The combination according to claim 1 wherein said apparatus includes a platform having guideway means thereon extending longitudinally and forwardly of said inner and outer cutters, a workpiece feeder member is slidably mounted on said guideway means, and means are provided for reciprocating said feeder member to push successive workpieces through said cutters.

7. The combination according to claim 1 wherein endles chain means are mounted for movement of at least one strand thereof longitudinally toward said cutters, a workpiece feed table is mounted adjacent said chain means and alignable with said cutters, and a plurality of pusher members are-secured to said chain means at spaced locations therealong for successive 7 length of said chain strand is supported on both sides by a pair of rigid spaced restraining strips respectively, and said pusher members are maintained in workpiece engagement positions when on said strand by a cam strip mounted adjacent said strand and substantially coextensive therewith, said cam strip being positioned for engagement by camming means mounted on said pusher members, when the latter are on said chain strand.

9. The combination according to claim 2 wherein said outer cutter flange includes a concave arcuate portion extending from the outer periphery of said flange to a position adjacent the tubular cutting edge of said outer cutter and an array of elongated fragmenting teeth are formed on said arcuate portion, said teeth extending substantially from the outer periphery of said flange to said outer tubular cutting edge.

10. The combination according to claim 9 wherein the array of fragmenting teeth is twisted slightly between said flange periphery and said tubular cutting edge to facilitate cutting engagement of said fragmenting teeth with the outer waste portions of said workpiece.

11. The combination according to claim 2 wherein the forward face of said flange is provided with cutting teeth, and chopping members mounted on the outer periphery of said flange for fragmenting the outer waste material cut from said workpiece by said outer tubular cutter.

12. The combination according to claim 7 wherein said chain means include a pair of spaced chains each of said chains being mounted for movement of a strand thereof longitudinally toward said cutters, and sprockets therefor, an elongated workpiece table is mounted between said chains on transversely adjustable supports for moving said table transversely toward and away from said strands to align said workpiece with said cutters. 

1. A cutting apparatus the combination comprising a base, an elongated tubular inner cutter extending parallel to the base and rotatably supported in cantilever fashion from said base, a tubular outer cutter rotatably mounted on the base substantially concentrically of said inner cutter but spaced longitudinally from the point of cantilever support of said inner cutter, means for rotating said cutters, and means for feeding an elongated workpiece from which a tubuliform member is to be cut to said inner and outer cutters, said longitudinal spacing approximating the anticipated length of said workpiece.
 2. The combination according to claim 1 wherein said outer tubular cutter is provided with an outwardly extending flange thereon adjacent the cutting end thereof, said flange having cutting means thereon for fragmenting the outer waste material cut from said workpiece.
 3. The combination according to claim 1 wherein said inner cutter is tubular and has an opening at each end in order to accommodate inner waste material from said workpiece, and the rotating means for said inner cutter is provided with an aligned opening therethrough in communication with said inner cutter opening so that said inner waste material is pushed therethrough by succeeding workpiece inner waste material and out of said apparatus.
 4. The combination according to claim 3 wherein said inner cutter rotating means includes an adjustable chuck having a generally central opening extending longitudinally therethrough and an open ended tubular drive shaft secured to said chuck for rotation therewith, the opening of said tubular shaft communicating with said chuck opening therethrough with said tubular cutter opening.
 5. The combination according to claim 1 wherein said outer cutter is rotatably mounted upon a movable platform, said platform being supported by said apparatus and movable longitudinally thereon relative to said chuck, said platform being detachably secured at selected positions along the length of said apparatus to accommodate differing lengths of inner cutters secured in said chuck.
 6. The combination according to claim 1 wherein said apparatus includes a platform having guideway means thereon extending longitudinally and forwardly of said inner and outer cutters, a workpiece feeder member is slidably mounted on said guideway means, and means are provided for reciprocating said feeder member to push successive workpieces through said cutters.
 7. The combination according to claim 1 wherein endless chain means are mounted for movement of at least one strand thereof longitudinally toward said cutters, a workpiece feed table is mounted adjacent said chain means and alignable with said cutters, and a plurality of pusher members are secured to said chain means at spaced locations therealong for successive feeding of workpieces to said cutters.
 8. The combination according to claim 7 wherein the free length of said chain strand is supported on both sides by a pair of rigid spaced restraining strips respectively, and said pusher members are maintained in workpiece engagement positions when on said strand by a cam strip mounted adjacent said strand and substantially coextensive therewith, said cam strip being positioned for engagement by camming means mounted on said pusher members, when the latter are on said chain strand.
 9. The combination according to claim 2 wherein said outer cutter flange includes a concave arcuate portion extending from the outer periphery of said flange to a position adjacent the tubular cutting edge of said outer cutter and an array of elongated fragmenting teeth are formed on said arcuate portion, said teeth extending substantially from the outer periphery of said flange to said outer tubular cutting edge.
 10. The combination according to claim 9 wherein the array of fragmenting teeth is twisted slightly between said flange periphery and said tubular cutting edge to facilitate cuttIng engagement of said fragmenting teeth with the outer waste portions of said workpiece.
 11. The combination according to claim 2 wherein the forward face of said flange is provided with cutting teeth, and chopping members mounted on the outer periphery of said flange for fragmenting the outer waste material cut from said workpiece by said outer tubular cutter.
 12. The combination according to claim 7 wherein said chain means include a pair of spaced chains each of said chains being mounted for movement of a strand thereof longitudinally toward said cutters, and sprockets therefor, an elongated workpiece table is mounted between said chains on transversely adjustable supports for moving said table transversely toward and away from said strands to align said workpiece with said cutters. 